Apparatus for coating pipes



J y 3, C. K. SMITH APPARATUS FOR COATING PIPES 9 Sheets-Sheet 1 Filed April 25, 1960 IN VEN TOR.

ATTORNEY July 3, 1962 SMITH 3,041,700

APPARATUS FOR COATING PIPES MKW ATTOAA/f July 3, 1962 c. K. SMITH I 3,

APPARATUS FOR COATING PIPES Filed April 25, 1960 9 Sheets-Sheet 3 Pg- I" .KIIHHHH .IIHI

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Am /f6 \62 Car/ J 07/ 1% INVENTOR.

July 3, 1962 I c. K. SMITH 3,041,700

APPARATUS FOR COATING PIPES.

Filed April 25, 1960 9 Sheets-Sheet 4 Car/ Jm/ffi INVENTOR.

BMEW

ATTOF/Vfy July 3, 19.02 SMITH 3,041,700

APPARATUS FOR COATING PIPES Filed April 25, 1960 '9 Sheets-Sheet 5 Car/ Jm/ffi INVENTOR.

ATTORNEY J l ,3 19 2 c. K. SMIQTH 3,041,700

APPARATUS FOR COATING PIPES i Filed April 25, 1960 9 Sheets-Sheet 6 Cc vr/ K Jm/ f/7 INVENTOR.

ATTORNEY July 3, 1962 03,041,700

c. K. SMITH APPARATUS FOR COATING PIPES Filed April 25, 1960 9 Sheets-Sheet 7 1/ WWMAF ,5 4

, (o// Jm/ffi INVENTOR.

A ITOR/VE r Jul 3, 1962 (ar/ Jaw/A INVENTOR;

ATTO/F/VEV July 3, 1962 c sMlTH APPARATUS FOR COATING PIPES Filed April 25, 1960 9 Sheets-Sheet 9 Car/ /K. Jm/f/z INVENTOR.

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ATTORNEY United States Patent 075cc l 3,041,700 APPARATUS FOR COATING PIPES Carl K. Smith, 133 Gibson Lane, Corpus Christi, Tex. Filed Apr. 25, 1960, filer. No. 24,481 2 Claims. (Cl. 25-38) This invention relates to the coating of pipe and more particularly to apparatus for applying to the external surface of metal pipes a protective and weighting coating.

In the application of protective and weight increasing coatings to pipes, as heretofore commonly practiced, it has been customary to apply such coatings by spraying or impelling the coating material against the external surface of the pipe While simultaneously moving the pipe longitudinally past the coating'apparatus and rotating the pipe. Coatings of various kinds, such as asphalt and concrete, have been successfully applied in this manner to metal pipes for the purpose of protecting such pipe from corrosion and weighting the same to prevent the pipe from floating when installed beneath water or in marshy ground. Ordinarily, pipe for such use is first coated with a corrosion' resistant coating, such as asphalt and is thereafter covered with a thick layer of heavy concrete containing suitable weighting material, such as barite or other heavy aggregate material. H

The treatment of pipe in this manner requires the use of two separate coating operations involving costly machinery and the exercise of close control over the operations which greatly adds to the labor and expense and increases the expenditure of time.

When a protective coating, such as asphalt, is employed, it is usually applied in a liquid condition, so that it becomes necessary to allow the coating to set or harden, or to employ other means of preventing the disruption of the coating during subsequent treatment or handling. The application of heavy concrete to pipe is carried out Whilethe concrete is in an unset condition and of relatively soft consistency such that the coating is easily scraped off or broken, so that careful handling and storage of the coated pipe becomes necessary to allow setting and proper hardening of the coating before the pipe can be safely transported.

The present invention has for an important object the provision of apparatus for the coating of pipe,'whereby a protective and weight increasing coating, having greatly improved durability, may be applied to the pipe in a single pass of the pipe through the machine,

Another object of the invention is to provide apparatus for coating pipe embodying the application to the pipe of a combined corrosion resistant and weight imparting coating, whereby the use of multiple coats is avoided and a coating of improved hardness, durability and resistance is obtained.

A' further object of the invention is the provision of pipe coating apparatus by which a hard, durable and corrosion resistant coating may be applied and compacted upon the external surface of pipe, and which enables the pipe to be immediately handled without danger of injury to the coating.

Another object of the invention is'to provide coating applying apparatus having means for moving a pipe longitudinally therethrough and including means for applying a relatively dense and substantially non-flowing coat ing material to be the exterior of the pipe and extruding the coating material in contact with the pipe as the pipe moves through the machine to compact the coating on the pipe to form thereon a dense and durable coating.

A further object of the invention is the provision in a pipe coating machine of the kind referred to of means'for supporting lengths of pipe in end to end axial alignment for substantially continuous movement through the maj Patented July 3, 1 952 chine and including means for rapidly conveying away the individual lengths of pipe after they have been coated.

Another object or the invention is to provide conveyor mechanism for use with pipe coating apparatus of the type mentioned by which lengths of pipe may be quickly assembled in end-to-end axial alignment and moved longitudinally' at a constant rate through the machine and including means for maintaining the lengths of pipe in axial alignment during coating of the same and for quickly and easily conveying away each length as soon as it has been coated. i A further object of the invention is the provision of coating apparatus for pipes comprising a stationary part positioned to surround a pipe and through which the pipe may be moved longitudinally, a rotatably mounted part positioned in surrounding relation to the pipe and shaped to act upon a coating material applied to the exterior of the pipe to propel the material longitudinally with the pipe and means on the stationary part positioned to be engaged by the material to compact the material against the pipe as the pipe and material move through the parts.

The above and other important objects and advantages of the invention may best be understood from the following detailed description, constitutinga specification of the same, when considered in conjunction with the annexed drawings, wherein- FIGURES 1 to 4, inclusive, are side elevational views on a reduced scale showing the overall arrangement of the pipe coating apparatus of. the invention and illustrating various stages of the method by which the coating operation is carried out;

FIGURE 5 is a plan view, partly broken away and partly in cross-section of the coating material feeding and compacting mechanism of the invention;

FIGURE 6 isfla cross-sectional view, taken along the line 6-6 of FIGURE 5, looking in the direction indicated bythe arrows;

FIGURE 7 is a side elevational view of the coating feeding and applying mechanism, as shown in FIGURE 5;

FIGURE 8 is a cross-sectional view taken along the line 8-8 of FIGURE 5, looking in the direction indicated by the arrows;

FIGURE 9 is a cross-sectional view, taken along-the line 9-9 of FIGURE 5, looking in the direction indicated by the arrows; v

FIGURE 10 is a cross-sectional view, taken along the line 10-10 of FIGURE 7, looking in the direction indicated by' the arrows;

FIGURE 11 is a perspective view, on a somewhat enlarged scale, of the rotatable feeding and compacting member of the invention;

FIGURE 12 is aside elevational view, partly in crosssection, of the pipe propelling mechanism of the invention; v

FIGURE 13 isakross-sotional view, taken along the line 13-13 of FIGURE 12, looking in the direction indicated by the arrows;

FIGURE-l4 is a cross-sectional view, takenalong the line 14-14 of FIGURE 12, looking in the direction of the arrows;

FIGURE 15 is a side elevational view, partly in cross- FIGURE 17 is a front end elevational View of the pipe supporting carriage of FIGURE 16, as seen from the left side of FIGURE 16;

FIGURE 18 is a fragmentary perspective view of the I 1 surface of the pipe.

FIGURE 19 is a front elevational View, partly broken away and one. somewhat enlarged scale, showing details of structure of the cable Winding mechanism of FIG- URE l8;

FIGURE 20 is a cross-sectional view, taken along the line 20-20 of FIGURE 5, looking in the direction indicated by the arrows; and

FIGURE 21 is a fragmentary perspective View, on a somewhat enlarged scale, illustrating a portion of the 'reenforcing wire Winding mechanism as seen in FIG- URE 20 and showing details ofstructure thereof.

Referring now to the drawings in greater detail, the invention is disclosed herein in connection with its use in the coating of pipes, suchas the steel pipes used in the construction of pipelines,'whichare buried in the ground and particularly the coating of such pipes with a durable and relatively hard coating of protective and weighting material, for example,a material made up of about 75% of an aggregate consisting of sand and gravel comminuted shell, or the like, 25% hydraulic cement,

' 7% asphalt and water. Such a composition contains relatively little water and is substantially non-flowing, so that it is unsuitable for application to the pipe without compressing or compacting the material on the external the support frame 28, and provided with nuts 38, threaded on their upper ends, whereby the lower frame may be moved vertically to move the rollers 34 into clamping engagement withthe pipe P.

Each pair of the rollers 34 is carried by a shaft similar to the shafts 14, rotatably' mounted in suitable bearings 4-2, and the shafts 46 are provided with sprockets 44 about which drive chains 46 extend, to cause the rollers to rotate simultaneously. Suitable means, such as electric motors 48 are provided, which operate through right angled drives 5i? to actuate drive chains 52 which pass about additional sprockets 54 on certain of the shafts 40, whereby the rollers 34 are rotated. By this arrangement, the pipe P may be tightly engaged between the sets of rollers 34 and the speed of the rollers may be regulated to feed the pipe P through the feeding mechanism at any desired speed. I

In operating the pipe supporting and longitudinally feeding mechanism of theinvention, the sections of pipe P may be assembled on the bed on the rollers 12 and suitably connected together, as by means of tapered plugs 56, to hold the pipe sections in horizontalalignment. The rollers 12 may then be operatedby the motor 26 to extend the pipe through the feeding mechanism, whereupon the rollers 34 may beclampingly engaged with thepipe by actuation of the nuts 38, so that the It will be understood, of: course, that the example given above is intended merely for the purpose of illustration and that substantial modification of the composition,

both as to the character of the ingredients'used andfthe proportions of the same, may be employed by the use to accomplish the purposes of the'invention. A composition of this character, when applied to a pipe 'by the'method of the invention, provides aprotective and weight imparting coating of greatly improved durability and hardness, while at the same time the coating pos sesses sufiicient flexibility to permit transportation and handling of the pipe without cracking or disintegration of the coating. A coating. of this kind also possesses the advantage that its hardnessincreases substantially with age, so that the coating eventually attains ,a hardness approaching that of concrete. I 1 The apparatus of the invention includes a supportmg structure or bed, which may conveniently be made up of sectional frames, 19, of rectangular construction adapted to be positioned in endwise abutting engagement and shafts being provided with sprockets 16, as best shown in FIGURE 15, about which drive chains18 may pass for the purpose of rotating therollerssimultaneously to.

move the pipe along the bed. Suitable means may be provided, such as an electric motor 29, drivingly connected toa right angled drive 22, which is in turn con:

nectedto a drive chain 24, which passes over an addl-' tional sprocket 26 on oneof the shafts 14, whereby'the rollers 12 may be rotated at any desired speed to control the movement of the pipe along the bed.

At one end of the bed, an additional supporting frame 28 .is positioned, through which the pipe P may move and which is provided upper and lower sets 30 and 32 of longitudinally spaced pairs of rollers 34, similar to the pairs ofrollers. 12, the lower set 32 of the rollers '34 being vertically movable relative to the upper set 30,

as by means of screw threaded rodsfio attachedat their "lower ends to' the lower set and ext ending vertically upwardly through suitable openings in cross members of of the method of the invention and the apparatus thereof driving, rollers 34 maybe operated by the motors 48 to feed the pipe at any desired rate. It will be apparent that by operating the supporting rollers 12, at a speed somewhat greater than the speed of the feeding rollers 34, the sections'ofpipe may be maintained in abuttingrelation, so that a continuous string of pipe may be moved into the feeding mechanism, the rollers 12 being capable of slipping relative to the pipe to hold the sections against becoming separated during the feeding of the pipe through the apparatus.

The coating applying mechanism of the invention, indicated at 60, in FIGURES 1 to 4, is located beyond the outlet end of the pipe feeding mechanism, and is supported on suitable framework of generally rectangular construction, which may include ground contacting skids 62, by which the coating mechanism as a unit may be readily moved about to properly position it in longitudinal alignmentwith the pipe supporting bed and feeding mechanism. The frame of the coating applying mechanism includes upright frame members 64, which may be suitably tied together at their upper ends, as by, means of a top plate 66, or otherwise. Vertically posi- I tioned plates 68 and 70 are attached to the inner faces of the upright 64, as bymeans of bolts v72 extending through vertically elongated slots 74 in the plates, and

provided with nuts 76, whereby the plates may be adjusted vertically to the uprights. The plates extend beyond the uprights at one side of the coating mechanism, to provide spaced apart flanged portions 78, serving as supports for certain par-ts of the coating mechanism, to be more particularly described hereinafter.

The plates 68 and 70 have central, circular openings 69 and 71 therethrough, as best seen in FIGURE 9, and circular headers and 82 are carried by the plates and provided'with central openings 81 and 83 therethrough which are in registration with the openings of the plates. The headers 80 and 32 may be attached to the plate by me'ans'of bolts 84, extending through the plates and headers and provided with nuts 86. The openings 81 and 83 of the headers form circular tr'ackways within which the opposite ends of 'a tubular driving element 88 extend, suitable roller bearings, such as those indicated at 90, as shown in FIGURE 9, being positioned between the ends of the element 88 and the trackways 81 and 83 to allow the element to rotate freely in the headers.

The header 8! also carries adjustable rollers 92, carried by'radially adjustable frames 94, slidably'attached to the header by means of certain of the bolts 84 to allow the rollers to be adjusted radially into engagement with the external surface of the pipe' P to center the pipe in the coating mechanism. The rotatably mounted, tubular driving element 88 is provided with sprocket teeth 96 about its external periphery, as shown in FIGURES 7 and 9, about which drive chains 98 extend, by which the element 88 is rotated.

As best seen in FIGURE 9, one end of the driving element 88 is internally threaded to receive a material compacting sleeve 100, which is carried by the driving element for rotation therewith and extends longitudinally beyond the header 82. The material compacting sleeve 100 is shown on an enlarged scale in FIGURE 11, and is formed with an external annular flange 102, mediate its ends and is cut away at one end to form helically or angularly shaped end faces 104 and lateral notches 106, which are preferably semi-circular in shape. The end faces 104 form pressure faces which are positioned to engage the coating material and coact therewith to move the coating material longitudinally in contact with the external surface of the pipe upon rotation of the compacting sleeve as the pipe moves longitudinally through the coating mechanism. An external confining rights 64, the plate being adjustable vertically in the same sleeve 108 is provided, surrounding the outer end portion of the compacting sleeve 104, which confining sleeve is carried by a support plate 110, having openings through which the bolts 84 pass upon which nuts 112 are threaded, to hold the confining sleeve centralized about the compacting sleeve. The confining sleeve may be attached to the support plate by radially extending gussets 114. The confining sleeve 108 has an internally restricted portion 116 near its outer end, through which the coating material is extruded by the longitudinal force exerted thereon by the pressure faces 104 of the compacting sleeve and the movement of the pipe through the coating mechanism to firmly compact the coating on the external surface of the pipe. The confining sleeve 108 has a lateral opening 118 through which an inlet pipe 120 opens into the interior of the confining sleeve, and within which a feed screw 122 is rotatably mounted on a shaft 124, by which the coating material is fed into the interior of the confining sleeve. The inlet pipe 120 has an upwardly extending branch pipe 126, through which coating material is supplied to the inlet pipe from any suitable source, such as a hopper, not shown.

. The rotation of the compacting sleeve 100 and th material feeding screw 122 is accomplished by suitable driving mechanism which may include an electric motor 128 which, in the present illustration, drives a counter.

shaft 130, operatively connected to a countershaft 132 as by means of a driving chain 134, the countershaft 132 being drivingly connected to the shaft 136 of a right angled drive 138, as by means of a drive chain 140. The right angled drive 138 in turn rotates an upper countershaft 142, which carries a sprocket 144, drivingly connected by a drive chain 146 to a sprocket 148 on the shaft 124 of the screw 122, wherebythe screw is rotated.

The countershaft 132 also carries sprockets 150, mediate its ends about which the chains 98 operate, which chains pass about the external sprocket teeth 96 of the driving element 88 with which the compacting sleeve 100 is rotatable.

. vided, suitably connected to the driving mechanism which connects the upper countershaft142 to the material feeding screw 122, which clutch mechanism may have an operatingrod 188, connected to 'a lever 160, pivotally mounted on the top plate 160 adjacent the lever 156, whereby the operation of the material feeding mechanism may be started or stopped independently of the manner as the plates 68 and 70, previously described, which plate has a central opening 170, about which a tubular extension 172 extends, whose free end is positioned close to the outer end of the confiningsleeve 108, the opening being in axial alignment with the confining sleeve. Circumferentially spaced rollers 174 are rotatably supportedon journals 176' on the plate 166 in surrounding relation to the opening 170, upon which rollers a gear ring 178 is supported in concentric relation to the opening for rotation on the rollers. The ring 178 is rotated by a drive chain 180, which passes about the ring and about the sprocket 182 carried on the shaft of an electric motor 184.

The ring 178 carries rotatably mounted spools 186 upon which reenforcing wire is wound and the ring also carries a wire guiding mechanism 188 for each of the spools, including rotatable pulleys 190, mounted on brackets, such as the bracket 192, shown in FIGURE 21, about which the wires 194 from the spools is fed, to wind the wires about the pipe P upon rotation of the ring 178, to imbed the wires in the coating. The wires 194 extend between the adjacent ends of the cylindrical extension 172 and confining sleeve 108 and may be anchored to the pipe in any suitable manner as by spot'welding the ends of the wires to the pipe, so that upon rotation of the ring 178, the wires will be Wound .off of the spools 186 and imbedded in the coating on the pipe.

For the purpose of conveying away sections of the pipe to which the coating has been applied, conveyor mechanism is provided, such as that shown generally at the left hand of FIGURES 1 to 4, inclusive, and details of whose construction is illustrated in FIGURES 16 to 19, inclusive. The conveyor mechanism includes a track having rails 196; extending longitudinally beyond the discharge end of the coating applying mechanism and upon which pipe supporting carriages 198 and 200 are sup-' cated'at the outer ends of the track and about separate portions 208 and 210 of an elongated winding drum 212, which is rotatably mounted adjacent the discharge end of the coating applying mechanism. The portions 208 and 210 of the winding drum are defined by pairs of longitudinally spaced annular'flanges 214 on the drum, between'each pair of whicha wire 216 is spirally wound on the drum to form an external thread with which the cable is engageable to cause the cableto be wound spirally onthe drum, as best seeniin FIGURE 19. The ends of each cable may be suitably anchored to the drum as by means of U-bolts 218 and 220.

The drum is suitably supported for rotation on a shaft 222- rotatably mounted in suitable bearings, and which is provided with driving mechanism, which takes the form of an electric motor 224located beyond one end of the shaft'and connected in driving relation thereto, in anyconventional manner, such as by the use of sprockets attached to the shaft 222 and to the shaft 226 of the motor anda drive chain which passes about the sprockets and which may be enclosed within a guard 228. The

direction and at any desired speed.

motor 224 may be operated to rotate the drums in either The other end of the shaft 222 is connected in driving relation to Suitable brake mechanism, which may take the form of an electric motor 230, suitably connected in driving relation to the shaft as by means of enclosed chain drive mechanisms 232 and 234 of conventional design, Which are connected together by means of a right angled drive 236. The brake mechanism is connected to the shaft in a manner'to control and restrain the rotation of the shaft during the movement of the carriage 198 away from the coating applying mechanism and suit-' able automatic clutch mechanism of conventional design generally indicated at 238 is provided, whereby the brake is disconnected from the shaft 222 during the return movement-of the carriage 198,,to permit the carriage to be returned quickly.

The carriage-198 is provided with means for anchoring the end of a section of the pipe P to the carriage against rotational movement relative thereto, which anchoring means may conveniently take the form of an arcuate saddle 240 mounted on the carriage in position to receive the end of the pipe, as illustrated in FIGURES l6 and 17. The saddle may be lined with a suitable material, such as brick lining, shown at 242, upon which the pipe rests and the saddle also carries a releasable the pipe in tight engagement with the saddle.;The clamp 244 has a releasable latch, provided with a lever 246, by which the clamp'may be quickly tightened or released.

The carriage 200 is provided with a'centrally positioned saddle 248, which is suitably mounted for vertical adjustment, to position the saddle in engagement with the coating on thepipe at any desired location, whereby a section of the pipe which has been coated maybe supported on the carriages 198 and 200 in a substantially horizontal position for movement along the track to a desired storage location.

In the operation of the inventiomconstructed and arranged as described above, sections of, the pipe P are positionedon the pipe supportingmechanism, resting upon the rollers 12 thereof and are connected together a in axial abutting relation by inserting" the tapered plugs 56 into the ends 'of' the sections, the rollers 12 beingrotated to move the connected sections along the bed toward the pipe feeding mechanism at a rate slightly in'ex! cess of the rate at which the pipe moves through the feedj ing mechanism to prevent the sections separated;

from becoming The continuous length o f pipe, thus provided, is moved 7 into. the pipe feeding mechanism and the rollers 34 the pipe coating mechanism. i

v The foremost one of the pipe sections is extended by the pipe feeding mechanism into the pipe coating mech' anism until an uncoated portion, of suitable length, of

the front end of the section is extended beyond the'confining sleeve 108, after which the coating applying mech-' anism is actuated to rotate'the compacting sleeve 19% while feeding the coating material against the external surface of the pipe by=means of the feed screw 122. During the feeding of the coating material and the rotation of the compacting sleeve 100, the feeding material Will pass through the openings or notches 106 of the compacting sleeve into contactvwith the external surface and moved'in the same direction as the pipe by the pressure faces 104 of the compacting sleeve. As the ma terial is thus fed into the coating apparatus and-acted forwardly to carry the coating material with it into the restricted portion 116 of the confining sleeve 108,.so

that under the influence of the movement of the pipe 8 and the compacting force exerted on the material by the compacting sleeve, the material will be strongly oompacted against the pipe and extruded through the re.- stricted portion 116 to compress the material on the pipe.

7 By providing a coating'material of suitableconsistency,

the material will be solidly compacted on the pipe to form a relatively hard and durable coating C of a charactor to permit handling of the pipe and storage of the same .without disintegration or other injury to the coat- As the pipe moves out of the coating applying mechanism, the uncoated front end portion F of the pipe will be moved into a. position to rest upon the saddle 240 of the carriage 198, .the carriage 200 being then beneath the coated portion of the pipe. The uncoated end portion F is then clamped on the saddle 240 by tightening the clamp 244, and the carriage 198 is moved forwardly. by operation of the electric motor 224 to rotate the winding'drum under the restraining influence of the braking mechanism, which may be adjusted to rege ulate the movement of the pipe through the coating applying mechanism at a rate to assure the uniform application of the coating to the pipe.-

. clamp 244 which may be positioned over the pipe to hold 7 to astorage location. thus moved to storage, the carri-age 198 is quickly returned, bringing with it the carriage 200, to position the carriages to receive the next 'sectionof pipe.

When a section of pipe has been thus coated for a substantial part of its length, the saddle 248 of the carriage 206) is elevated to engage the coating to support the pipe in a substantially horizontal position in axial alignment with subsequent'sections of pipe in the apparatus, and as soon as the coating on one section has been completed, the coating applying mechanism is stopped and the pipe is further moved through the apparatus to leave a second uncoated end portion on the section, as will be clearly seen in FIGURE 3. The thus completely coated section of pipe is then moved away rain the coating applying mechanism by operation of the carriage 198, the pipe being supported in a horizontal position by the carriages 198 and 200 to convey the pipe When the coated section has been 'By repeating the above operations, it will be apparent 7 that sections of pipe may be coated in quick succession and moved to storage with a minimum of expense and labor. During the coating operation, the feeding of the coating material may be stopped at any desired point by actuation of the lever 160, so that the pipe may be moved through the apparatus without the application thereto of the coating, whereby the end portions of the pipe may be readily left in an uncoated condition.

Itwill also be apparent that the Wires 194 may, if desired, be wound about the coating to become imbedded therein during the coating of the pipe by actuation of the winding mechanism, as illustrated in FIGURES 5, ZOandZl. p, f In the event that it should be desired to provide a'coating of different thickness to the pipe or to coat a pipe of different outside diameter, this can be accomplished by removing the confining sleeve 108 and the compacting sleeve and'replacing these elements with others of suitable, size;

, It will thus be seen that the invention, constructed and operated as described above, provides inexpensive .of the pipe, and the coating material will be compacted upon bythe compacting sleeve, the pipe will be moved apparatus of simple design and rugged construction.

The invention is disclosed herein in connection with certain specific structures and arrangements of parts, but it will be understood that these are intended by way of illustration only and that numerous changes can be made in the construction and arrangement of the parts, within the spirit of the invention and the scope of the appended claims. a

Having thus clearly shoWn'and-described the invention, what is claimed as new and desired to secure by Letters Patent is- 1. Pipe ,coating apparatus comprising means for supmoves through the member, means on the member positioned for engagement with the material on the pipe to move the material with the pipe, a tubular element surrounding the member and through which the pipe may move in concentric relation to the element and formed with an internally restricted portion shaped for engagement with the material on the pipe to compress the material against the pipe.

2. Pipe coating apparatus comprising means for supporting a pipe for movement along a longitudinal axis, a tubular confining element surrounding the axis and through which the pipe may move in radially inwardly spaced, concentric relation to the element, means for applying a coating material to the external surface of the pipe in the element, a tubular member mounted for rotational movement about the pipe between the pipe and element and having a portion shaped for engagement with the material to move the material longitudinally with the pipe, said element having an internally restricted portion positioned for engagement with the material on the pipe as the pipe moves through the element to compress the material againstthe pipe.

References Cited in the file of this patent UNITED STATES PATENTS 2,053,307 Wilson Sept. 8, 1936 2,186,361 Bryan et a1. Jan. 9, 1940 2,236,757 Lines Apr. 1, 1941 2,279,340 Postlewaite Apr. 14, 1942 2,452,610 Sonnenfeld Nov. .2, 1948 2,553,481 Sharples May 15, 1951 2,588,595 'Warner Mar. 11, 1952 2,611,941 Leitl Sept. 30, 1952, 

